THIS! My wife was kidnapped in Rome by a fake cab when leaving the airport. Got in, and no door handles. She called me, starting to freak out, as she should. I had her turn on her FB messenger live location for me, and I had airtags in her backpage and one of her suitcases, because air travel. Had her put me on speakerphone and am using google translate to poorly tell the guy exactly what intersections he was at and that I had the Roman police on my other phone (Which I did!). Kept telling him, you need to stop going north and head east past the Vatican and over the river to her hotel. The driver had tried lying early on, but I kept it up... he called his boss / handler, whatever guy. Started speaking something not Italian, and they kept raising their voices with each other. Hung up, and still headed north. I let him hear me speaking with the police and he called his boss again, more yelling, and then he turned toward the river. Then south to take the bridge and finally to the hotel. Police were waiting for him and escorted my wife into the hotel.
She wasn't thinking when she'd left the airport, she was tired from her flight. Saw the long taxi line and this guy came up and offered her a taxi, and she went with it without thinking. Woke her right up once she saw the no door handles to get out. I will forever love airtags after that! Because even if he'd taken her phone, the suitcase in the back still had him at almost every intersection. We got damn lucky!
Get the local taxi app, car sharing app, whatever, and only use that. You want to encourage more taxi drivers to use apps so they can pick you up no matter where you are and give you a fair price.
I have a PacSafe backpack, and the thing is great for international travel. It's slash proof with lockable zippers and a detachable strap, so I can feel far more comfortable in areas known for pickpockets and thieves. It's also great as the only carry-on if you are checking luggage. A laptop fits in it, along with big noise canceling headphones and a jack and a book, plus the side pockets are good for a bottle to fill with water after security and a small umbrella. It has RFID blocking on it, too, which is good for digital thieves.
Don't try to hit too many places on a single trip, unless you are backpacking. Lugging around heavy luggage from one hotel to the next to the next to the next, from train to taxi to cobble stones to stairs, gets really really tiring. Try to have a minimum 3 night stay at each location or have pre-sorted clothing stuff bags packed so you can keep the heavy luggage in a rental car and just grab a single stuff bag with 2 days worth of clothing.